Which option is a mandatory softkey for a Cisco IP 7965, running SCCP firmware, in the Off Hook call state?

Which option is a mandatory softkey for a Cisco IP 7965, running SCCP firmware, in the Off Hook call state?
A. Redial
B. NewCall
C. EndCall
D. CfwdAll
E. There is no mandatory softkey in the Off Hook call state.